Report JVM signature clashes from JVM_IR

Also:

* Do not rename public ABI fields
This includes backing fields for const, lateinit, @JvmField properties,
and instance fields for objects.

* FAKE_OVERRIDE declarations for static members of parent Java classes
Required to report cases when a Kotlin function accidentally overrides
Java class member.

compiler/testData/diagnostics/testsWithJvmBackend/duplicateJvmSignature/specialNames/enum.kt

@@ -0,0 +1,7 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+enum class <!CONFLICTING_JVM_DECLARATIONS, CONFLICTING_JVM_DECLARATIONS!>E<!> {
+    A;
+
+    <!CONFLICTING_JVM_DECLARATIONS!>fun values(): Array<E><!> = null!!
+    <!CONFLICTING_JVM_DECLARATIONS!>fun valueOf(s: String): E<!> = null!!
+}